scholarly journals Modelling and Analysis of a Magnetorheological Damper with Nonmagnetized Passages in Piston and Minor Losses

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Guojie Li ◽  
Ze-Biao Yang
Keyword(s):  
Mathematical Model ◽  
Pressure Drop ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Mr Fluid ◽  
Pressure Drops ◽  
Viscous Loss ◽  
Minor Losses ◽  
The Mathematical Model

This work aims to establish the mathematical model with the high effectiveness in predicting the damping force of an MR damper with nonmagnetized passages in piston. The pressure drops due to viscous loss, MR effect, and the minor losses at the inlet and outlet of passages are considered in the mathematical model. The widely reported Bingham model is adopted to describe the mechanical property of MR fluid. The mechanical behaviours of the MR damper are experimentally evaluated under different excitations and current. The yield stress of MR fluid with respect to the current applied to piston coil is obtained by finite element analysis in Ansoft Maxwell 14.0. The proposed model is validated by comparing the simulated damping characteristics with the measured data under various currents applied to the piston coil. The simulated results are also compared with those obtained from the mathematical model without the pressure drop due to the minor losses at the inlet and outlet of passages. The comparisons show that the proposed mathematical model can yield more accurate predictions of damping force. This indicates that the pressure drop due to the minor losses is significant and nonnegligible. The nonlinearity of force-velocity characteristics is discussed. In order to quantitatively explain the necessity of taking the minor losses into account for modelling the MR damper, the proportion of pressure drop due to the minor losses to the total pressure drop is investigated and discussed. Pressure drops due to the minor losses and viscous loss are also investigated and discussed. At last, the proposed mathematical model is used to analyse the working principle of nonmagnetized passages.

Experimental Evaluation of Magnetorheological Damper Characteristics for Vibration Analysis

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
S. Siva Kumar ◽  
K.S. Raj Kumar ◽  
Navaneet Kumar
Keyword(s):  
Vibration Isolation ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Mr Fluid ◽  
Damping Characteristics ◽  
Fluid Damper ◽  
Mr Fluid Damper ◽  
Stiffness And Damping ◽  
Theoretical Results

Magnetorheological (MR) fluid damper has been designed, fabricated and tested to find the stiffness and damping characteristics. Experimentally the MR damper has been tested to analyse the behaviour of MR fluid as well as to obtain the stiffness for varying magnetic field. MR damper mathematical model has been developed for evaluating dynamic response for experimentally obtained parameters. The experimental results show that the increase of applied electric current in the MR damper, the damping force will increase remarkably up to the saturation value of current. The numerical simulation results that stiffness of the MR damper can be varied with the current value and increase the damping forces with the reduced amplitude of excitation. Experimental and theoretical results of the MR damper characteristics demonstrate that the developed MR damper can be used for vibration isolation and suppression.

Pneumotransport of Grains Through a Pipeline

2002 ◽  
Author(s):  
Kaushal K. Shrivastava
Keyword(s):  
Mathematical Model ◽  
Pressure Drop ◽  
Experimental Results ◽  
Experimental Techniques ◽  
Horizontal Pipe ◽  
Pressure Drops ◽  
Central Topic ◽  
The Mathematical Model ◽  
Mustard Seeds

Determination of pressure drop correlation using experimental techniques has been a central topic of research in the area of pneumotransport. However, the objective of the present investigation is to apply the mathematical model (SK model) developed by the author [1,2] along with other correlations [3–5] to estimate pressure drops for conveying varieties of grains through horizontal pipe and compare the values with the experimental results of Siegel [6]. The SK model has also been utilized to calculate pressure drops for conveying mustard seeds pneumatically through horizontal, inclined and vertical pipes and compare the values with the experimental results of Rose and Barnacle [7]. It is evident from various comparisons shown in this paper that the SK model predicts the values of pressure drop accurately as compared to the experimental results in all the cases of grains transport through horizontal, inclined, and vertical pipes, whereas, other correlations do not predict accurate results consistently in all cases.

scholarly journals Dynamic Analysis of Sphere-Like Iron Particles Based Magnetorheological Damper for Waveform-Generating Test System

2020 ◽  
Vol 21 (3) ◽  
pp. 1149 ◽  
Author(s):  
Jong-Seok Oh ◽  
Chang Won Shul ◽  
Tae Hyeong Kim ◽  
Tae-Hoon Lee ◽  
Sung-Wan Son ◽  
...  
Keyword(s):  
Mr Damper ◽  
Test System ◽  
Double Pulse ◽  
Magnetorheological Damper ◽  
Force Model ◽  
Pulse Waveform ◽  
Iron Particles ◽  
Damping Force ◽  
Mr Fluid ◽  
Fundamental Parameters

In this study, a new double pulse waveform-generating test system with an integrated magnetorheological (MR) damper is proposed. Since the total shear stress of MR fluid can be varied according to the shape of particles, sphere-like iron particles-based MR fluid is filled into the MR damper. The test system consists of a velocity generator, three masses (impact, test, and dummy), a spring, and an MR damper. To tune the double pulse waveform profile, a damping force model is constructed to determine the fundamental parameters of the simulator. Then, the first and second shock waveform profiles are analyzed to solve the governing equation of motions representing the damping force and velocity. The mathematical model of the MR damper is formulated and applied to a simulator with a graphical user interface programmed using MATLAB. The effectiveness of the proposed simulator-featuring controllable MR damper is demonstrated by comparing the simulation and experimental results.

Damping characteristics of a magneto-rheological damper with dual independent controllable ducts

2021 ◽  
pp. 1045389X2110188
Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou
Keyword(s):  
Dynamic Range ◽  
Fluid Flows ◽  
Mr Damper ◽  
Viscous Damping ◽  
The Novel ◽  
The Finite Element Method ◽  
Damping Force ◽  
Damping Characteristics ◽  
Magneto Rheological ◽  
The Mathematical Model

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.

scholarly journals Design and multi-physics optimization of a novel magnetorheological damper with a variable resistance gap

2016 ◽  
Vol 231 (17) ◽  
pp. 3152-3168 ◽  
Author(s):  
Jiajia Zheng ◽  
Yancheng Li ◽  
Jiong Wang
Keyword(s):  
Optimization Problem ◽  
Dynamic Range ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Voltage Source ◽  
Damping Force ◽  
Variable Resistance ◽  
Design Variables ◽  
Electromagnetic Coils ◽  
Vibration Performance

This paper presents the design and multi-physics optimization of a novel multi-coil magnetorheological (MR) damper with a variable resistance gap (VRG-MMD). Enabling four electromagnetic coils (EMs) with individual exciting currents, a simplified magnetic equivalent circuit was presented and the magnetic flux generated by each voltage source passing through each active gap was calculated as vector operations. To design the optimal geometry of the VRG-MMD, the multi-physics optimization problem including electromagnetics and fluid dynamics has been formulated as a multi-objective function with weighting ratios among total damping force, dynamic range, and inductive time constant. Based on the selected design variables (DVs), six cases with different weighting ratios were optimized using Bound Optimization BY Quadratic Approximation (BOBYQA) technique. Finally, the vibration performance of the optimal VRG-MMD subjected to sinusoidal and triangle displacement excitations was compared to that of the typical multi-coil MR damper.

Realization of desired damping characteristics based on an open-loop-controlled magnetorheological damper

2021 ◽  
pp. 107754632110388
Author(s):  
Hongwei Lu ◽  
Zhifei Zhang ◽  
Yansong He ◽  
Zhi Li ◽  
Jujiang Xie ◽  
...  
Keyword(s):  
Control System ◽  
Control Method ◽  
Characteristic Curve ◽  
Mr Damper ◽  
Open Loop ◽  
Low Noise ◽  
Magnetorheological Damper ◽  
Bench Test ◽  
Damping Force ◽  
Damping Characteristics

The realization of the desired damping characteristics based on magnetorheological (MR) dampers is important for semi-active control and useful for the matching process of suspension damper. To reduce the cost of the control system and improve the output accuracy of the desired damping force, this study proposes an open-loop control method featuring an accurate inverse model of the MR damper and a tripolar current driver. The reversible sigmoid model is used to accurately and quickly calculate the desired current. Furthermore, the change characteristic of the desired current is analyzed qualitatively and quantitatively, which shows that the desired current needs to change suddenly to make the actual damping force velocity curve quickly approach the desired one. To meet the demand of the desired current, a tripolar current driver controlled by an improved PI control algorithm is proposed, which is with fast response and low noise. Finally, the bench test verifies that the control system can achieve different desired damping characteristics well, and the inherent error in this process is explained through the gap between the available damping force area and the desired damping characteristic curve and the crossover phenomenon of the dynamic characteristic curves of the MR damper.

scholarly journals Design of a Novel Magnetorheological Damper Adaptable to Low and High Stroke Velocity of Vehicle Suspension System

2020 ◽  
Vol 10 (16) ◽  
pp. 5586
Author(s):  
Bo-Gyu Kim ◽  
Dal-Seong Yoon ◽  
Gi-Woo Kim ◽  
Seung-Bok Choi ◽  
Aditya Suryadi Tan ◽  
...  
Keyword(s):  
Shape Function ◽  
Mr Damper ◽  
Effective Area ◽  
Magnetorheological Damper ◽  
Damping Coefficient ◽  
Vehicle Suspension ◽  
Damping Force ◽  
Piston Velocity ◽  
Suspension Systems ◽  
Vehicle Suspension System

In this study, a new class of magnetorheological (MR) damper, which can realize desired damping force at both low and high speeds of vehicle suspension systems, is proposed and its salient characteristics are shown through computer simulations. Unlike conventional MR dampers, the proposed MR damper has a specific pole shape function and therefore the damping coefficient is changed by varying the effective area of the main orifice. In addition, by controlling the opening or closing the bypass orifice, the drastic change of the damping coefficient is realizable. After briefly describing the operating principle, a mathematical modeling is performed considering the pole shape function which is a key feature of the proposed MR damper. Then, the field-dependent damping force and piston velocity-dependent characteristics are presented followed by an example on how to achieve desired damping force characteristics by changing the damping coefficient and slope breaking point which represents the bilinear damping property.

scholarly journals Design and Multiobjective Optimization of Magnetorheological Damper considering the Consistency of Magnetic Flux Density

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Zhizhen Dong ◽  
Zhimin Feng ◽  
Yuehua Chen ◽  
Kefan Yu ◽  
Gang Zhang
Keyword(s):  
Magnetic Flux ◽  
Multiobjective Optimization ◽  
Flux Density ◽  
Optimization Design ◽  
Dynamic Range ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Magnetic Flux Density ◽  
Damping Force ◽  
Mr Dampers

The consistency of magnetic flux density of damping gap (CMDG) represents the balancing magnetic flux density in each damping gap of magnetorheological (MR) dampers. It can make influences on the performances of MR dampers and the accuracy of relevant objective functions. In order to improve the mechanical performances of the MR damper with a two-stage coil, the function for calculating CMDG needs to be found. By establishing an equivalent magnetic circuit model of the MR damper, the CMDG function is derived. Then, the multiobjective optimization function and the working flow of optimal design are presented by combining the parallel-plate model of the MR damper with the function posed before. Taking the damping force, the dynamic range, the response time, and the CMDG as the optimization objective, and the external geometric dimensions of the SG-MRD60 damper as the bound variable, this paper optimizes the internal geometric dimensions of MR damper by using a NSGA-III algorithm on the PlatEMO platform. The results show that the obtained scheme in Pareto-optimal solutions has existed with better performance than that of SG-MRD60 scheme. According to the results of the finite element analysis, the multiobjective optimization design including the CMDG function can improve the uniformity of magnetic flux density of the MR damper in damping gap, which meets the requirements of manufacture and application.

Comparative Study of Magnetorheological Damper Models for Force Tracking

2015 ◽  
Author(s):  
Anria Strydom ◽  
Werner Scholtz ◽  
Schalk Els
Keyword(s):  
Computational Efficiency ◽  
Ride Comfort ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Suspension Systems ◽  
Mr Dampers ◽  
Damping Characteristics ◽  
Force Tracking ◽  
Control Application

Magnetorheological (MR) dampers are controllable semi-active dampers capable of providing a range of continuous damping settings. MR dampers are often incorporated in suspension systems of vehicles where conflicting damping characteristics are required for favorable ride comfort and handling behavior. For control applications the damper controller determines the required damper current in order to track the desired damping force, often by using a suitable MR damper model. In order to utilise the fast switching time capability of MR dampers, a model that can be used to directly calculate damper current is desired. Unfortunately few such models exist and other methods, which often negatively affect the computational efficiency of the model, need to be used when implementing these models. In this paper a selection of MR damper models are developed and evaluated for both accuracy and computational efficiency while tracking a desired damping force. The Kwok model is identified as a suitable candidate for the intended suspension control application.

Application of Systematic Innovative Method to Improve the Structure of Magnetorheological Damper

2013 ◽  
Vol 284-287 ◽  
pp. 3586-3590 ◽  
Author(s):  
Chia Pao Chang ◽  
Ying Hsiang Lin ◽  
Yu Cheng Chen
Keyword(s):  
Mr Damper ◽  
Magnetorheological Damper ◽  
National Defense ◽  
Damping Force ◽  
Innovative Method ◽  
Engineering Parameters ◽  
Improved Design ◽  
Acting Force ◽  
The Magnetic Field ◽  
Different Levels

Magnetorheological fluid (MR fluid) has been widely used in the industrial fields, especially in the machinery, automobile, national defense and construction industries. Most of the researches of the Magnetorheological Damper only utilized device to examine the effects of different levels of voltage, amplitude and frequency on energy reduction. They find a combination of the number of circles of wire, damping tubes, enameled wire sleeves for liquid of MR damper controlled to increase the damping force. This study uses different ways to solve the problem. We think outside the box and apply the concepts and technology of systematic innovation method to improve the structure of the MR damper for increasing the effectiveness. This study uses the contradiction matrix, 39 engineering parameters, and 40 inventive and innovative principles to identify the areas of improvement to address the exist problems. Regarding the decrease of the magnetic field acting force due to increase of the moving distance and the effect on the magnetorheological damper efficiency. Finally, we propose an improved design of the MR Damper.

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